A reliable stretchable dry electrode for monitoring of EEG signals

Abstract

Biopotential Recording is an important parameter in studying, discovering, and diagnosing neurological disorders. Electroencephalogram (EEG) is recording of electrical activity of the human brain, typically performed, using surface electrodes. Commercial wet Ag/AgCl electrodes are the gold standard among surface electrodes. Nevertheless, these electrodes are inappropriate in wearable long-term applications mainly due to the use of conductive gels and inflexibility. Various types of dry electrodes are proposed in the literature to address the inherent disadvantages of wet electrodes. Yet few works in the state-of-the-art address mechanical reliability tests which is of paramount importance in real world wearable applications.In this manuscript, we have demonstrated a relatively inexpensive flexible and stretchable dry electrode to record the EEG. The electrode is formed in a 3D shape with 4 legs in order to increase the compliance to the skin as well as mechanical and electrical reliability. The electrical performance of the electrode is found to be similar to the standard wet Ag/AgCl counterpart. In addition to the typical tensile strength test, the mechanical endurance of the electrode is verified using a custom-designed stroke test in a relatively severe condition.